The present invention relates to the improvement of a discharge surface processing method for subjecting the end surface and the side surfaces of material to be processed such as a tool, a mechanical part etc. to the surface processing.
FIGS. 4(a), 4(b) and 4(c) are an example of a shearing processing which is a kind of a plasticity processing. In the figure, a reference numeral 1 depicts a punch, 2 a die, 3 a member to be processed, 4 the end surface of the punch 1, 4a the cut portions of the end surface 4 of the punch 1, 5 the side surfaces of the punch 1, and 5a the cut portions of the side surfaces 5 of the punch 1. As shown in FIGS. 4(a), 4(b) and (c), the shearing processing is performed in a manner that the punch 1 is pushed against the processed member 3 on the die 2 to thereby cut and separate the processed member 3. This processing method is called as a punching processing when the punched member is used as a product, while called as a boring processing when the remaining portion except for the punched portion is used as a product.
Such a shearing processing can process even such a produce with a complicated contour shape in a short time with a single process, so that the shearing processing has been widely employed as the technique for manufacturing various kinds of mechanical parts and secondary processing material. The punch used as a tool for such a plasticity processing is subjected to the surface processing on the end surface and the side surface thereof in order to make the life time thereof longer. In particular, the PVD, the CVD and the discharge surface processing are known as the surface processing methods capable of forming a hard coating film on the processed material. Of these surface processing methods, each of the PVD and the CVD has a problem that the scale thereof is large, the cost of the surface processing is high and it takes a long delivery time. Thus, the discharge surface processing is considered to be suitable for the surface processing of a punch.
FIG. 5 is an explanatory diagram showing the configuration in the discharge surface processing method disclosed in Japanese Patent Laid-Open No. 192937/1997. In the figure, a reference numeral 6 depicts a powdered electrode serving as a discharge surface processing electrode formed by compressing TiH2, 7 a material to be processed, 8 a processing bath, 9 a processing fluid, 10 a switching element for switching voltage and current applied to the powdered electrode 6 and the processed material 7, 11 a control circuit for controlling the on and off operations of the switching element 10, 12 a processing power source, and 13 a hard coating film formed on the processed material 7. A hard coating film with a large adhesion force can be formed on the surface of steel, sintered hard alloy etc. by using the discharge surface processing apparatus thus configured.
In recent years, precision machinery components such as toothed gears, cams etc. and electronic parts such as IC lead frames have been manufactured by the shearing processing. Thus, the punches with complicated configurations necessary for fabricating such products have been required to be longer in their life times.
Such a punch is required to subject the cut portions of the end surface thereof (4a of FIG. 4) and the cut portions of the side surface thereof (5a of FIG. 4) to the surface processings. However, for example, it is difficult to subject the A portion to the C portions of the side surfaces of the punch having the complicated configuration in the sectional view shown in FIG. 6 to the discharge surface processings. This is caused by such a reason that it is difficult to fabricate the powdered electrode serving as the discharge surface processing electrode with a particular configuration. In view of such a fact, the discharge surface processing can not be performed effectively as to the processed material such as a punch with a complicated configuration which is required to subjected its end surface and side surfaces to the surface processing.
The invention is performed so as to solve the aforesaid problem of the prior art, and an object of the invention is to obtain a discharge surface processing method which can effectively perform the discharge surface processing as to processed material such as a punch with a complicated configuration etc. which is required to subject its end surface and side surfaces to the surface processing.
Another object of the invention is to obtain a discharge surface processing method which can use processed material repeatedly with a simple modification and reduce a maintenance cost thereof.
The discharge surface processing method according to the invention is arranged in a manner that in the discharge surface processing method wherein an X axis driving device, a Y axis driving device and a Z axis driving device are controlled to be driven, material to be processed and a discharge surface processing electrode are moved relatively, and discharge energy is supplied between electrodes of the material to be processed and the discharge surface processing electrode to thereby form a hard coating film on the material to be processed, the discharge surface processing method includes:
a first step of controlling the Z axis driving device to be driven to generate discharge between an end surface of the material to be processed and the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed and a carved portion with a predetermined depth at the discharge surface processing electrode; and
a second step of, while controlling the X axis driving device and the Y axis driving device to be driven to orbit the material to be processed and the discharge surface processing electrode relatively, generating discharge between a side surface of the material to be processed and a side surface of the carved portion to thereby form, by electric discharge energy, a hard coating film on the side surface of the material to be processed.
Alternatively, in the discharge surface processing method wherein an X axis driving device, a Y axis driving device and a Z axis driving device are controlled to be driven, material to be processed and a discharge surface processing electrode are moved relatively, and discharge energy is supplied between electrodes of the material to be processed and the discharge surface processing electrode to thereby form a hard coating film on the material to be processed, the discharge surface processing method includes:
a step of controlling the X axis driving device, the Y axis driving device and the Z axis driving device to be driven to generate discharge between an end surface of the material to be processed and the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed; and, while orbiting the material to be processed and the discharge surface processing electrode relatively, generating discharge between a side surface of the material to be processed and a side surface of the carved portion to thereby form, by electric discharge energy, a hard coating film on the side surface of the material to be processed.
Alternatively, in the discharge surface processing method wherein an X axis driving device, a Y axis driving device and a Z axis driving device are controlled to be driven, material to be processed and a discharge surface processing electrode are moved relatively, and discharge energy is supplied between electrodes of the material to be processed and the discharge surface processing electrode to thereby form a hard coating film on the material to be processed, the discharge surface processing method includes:
a first step of controlling the Z axis driving device to be driven to generate discharge between an end surface of the material to be processed and the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed and a carved portion with a predetermined depth at the discharge surface processing electrode;
a second step of, while controlling the X axis driving device and the Y axis driving device to be driven to orbit the material to be processed and the discharge surface processing electrode relatively, generating discharge between a side surface of the material to be processed and a side surface of the carved portion to thereby form, by electric discharge energy, a hard coating film on the side surface of the material to be processed;
a third step of grinding the hard coating film formed on the end surface of the material to be processed; and
a fourth step of controlling the Z axis driving device to be driven to generate discharge between the end surface of the material to be processed and a flat surface portion of the discharge surface processing electrode except for the carved portion to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed.
Alternatively, in the discharge surface processing method wherein an X axis driving device, a Y axis driving device and a Z axis driving device are controlled to be driven, material to be processed and a discharge surface processing electrode are moved relatively, and discharge energy is supplied between electrodes of the material to be processed and the discharge surface processing electrode to thereby form a hard coating film on the material to be processed, the discharge surface processing method includes:
a first step of controlling the X axis driving device, the Y axis driving device and the Z axis driving device to be driven to generate discharge between an end surface of the material to be processed and the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed; then forming a carved portion with a predetermined depth at the discharge surface processing electrode and, while orbiting the material to be processed and the discharge surface processing electrode relatively, generating discharge between a side surface of the material to be processed and a side surface of the carved portion to thereby form, by electric discharge energy, a hard coating film on the side surface of the material to be processed;
a second step of grinding the hard coating film formed on the end surface of the material to be processed; and
a third step of controlling the Z axis driving device to be driven to generate discharge between the end surface of the material to be processed and a portion different from the carved portion of the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed.
Alternatively, in the discharge surface processing method wherein an X axis driving device, a Y axis driving device and a Z axis driving device are controlled to be driven, material to be processed and a discharge surface processing electrode are moved relatively, and discharge energy is supplied between electrodes of the material to be processed and the discharge surface processing electrode to thereby form a hard coating film on the material to be processed, the discharge surface processing method includes:
a step of grinding the hard coating film formed on the end surface of the material to be processed when the material to be processed is worn out; and
a step of controlling the Z axis driving device to be driven to generate discharge between the end surface of the material to be processed and the discharge surface processing electrode to thereby form, by electric discharge energy, a hard coating film on the end surface of the material to be processed.
Since the invention is configured in the aforesaid manner, the following technical advantages can be obtained.
The discharge surface processing method according to the invention can effectively perform the discharge surface processing also as to the material to be processed such as a punch with a complicated configuration etc. which is required to subject the end surface and the side surfaces thereof to the surface processing.
Further, the discharge surface processing method according to the invention can form a hard coating film with a higher accuracy.
Furthermore, the discharge surface processing method according to the invention can use the material to be processed repeatedly by performing a simple modification, so that the maintenance cost thereof can be reduced.